Views:354 Author:Cardan Shaft Manufacturer Publish Time: 2020-01-28 Origin:Sitong Cardan Shaft Co.,Ltd
What drum - shaped gear coupling demands on drum curve? The drum tooth surface of the non-conjugate tooth surface is formed by the gradual displacement of different end sections. The dotted line formed by the displacement and axial coordinates is called the drum curve. The drum curve is an important geometric parameter of the drum gear coupling. The drum curve is mostly one arc, or three arc. These circles are called drum circles. In the arc drum curve, some drum centers are on the gear axis, some are not on the axis; some drum circle centers coincide with tooth surface spherical centers, and some do not overlap. Generally speaking, the drum gear coupling of Jiangsu Sitong Cardan Shaft CO., LTD should meet the following requirements:
(1) There is no edge contact at the maximum dip angle between shafts.
(2) The less the concentrated load of gear teeth, the better. The curvature of tooth surface is directly proportional to the circumference of drum degree, so the radius of drum degree circle is as large as possible. The curvature radius of the drum curve is directly proportional to the one side thinning of the inner tooth, so the radius of the drum circle should be as large as possible. The curvature radius of the drum curve is directly proportional to the one side thinning of the inner tooth, that is, it is related to the meshing gap of the tooth. Insufficient thinning may cause interference, which will weaken the strength of the tooth and cause a large lateral gap.
Inner Gear Cycle
When the drum gear coupling works, relative angular displacement of the two shafts and relative axial sliding of the surface of the inner and outer teeth periodically will result in surface wear and power consumption. Therefore, the drum gear coupling needs to work in a good and sealed state. The NGCL type drum gear coupling is composed of the same number of teeth, the inner gear ring and the flange half coupling with the outer teeth. The outer teeth are divided into straight teeth and drum teeth. The so-called drum tooth is to make the outer tooth into a sphere, the spherical center is on the gear axis, the tooth side clearance is larger than the general gear, and the drum tooth coupling allows greater angular displacement (relative to the straight tooth coupling), which can improve the contact conditions of the teeth, improve the ability to transfer torque, and extend the service life.
Good lubrication is a necessary guarantee for the safe and reliable operation of the drum gear coupling and has the function of reducing wear. If the tooth root bending strength and contact strength of the tooth surface are sufficient, the tooth width should be determined with a high degree of coincidence. Generally, the tooth width coefficient is 8-14. The minimum tooth width should be determined by the allowable root stress and the required width of the point of impact caused by the dip between the axes along the tooth width displacement.
The important way to improve the service life of drum gear coupling: The tooth width coefficient affects the tooth root bending strength and contact strength of tooth surface. The greater the tooth width coefficient, the greater the strength of these two terms.The tooth width coefficient affects the coincidence degree, when the tooth width coefficient is less than a certain value, the increase of its value has a greater impact on the increase of the coincidence degree, while when it is greater than a certain value, the increase of the device value has a smaller impact on the increase of the coincidence degree. For the drum gear coupling of arc drum curve, the tooth width is still the parameter to determine the drum circle radius and side clearance. The larger the tooth width, the larger the drum circle radius, the larger the desired side clearance.
Therefore, drum gear coupling requires the following two requirements : 1. Tooth concentrated. 2. The smaller the load, the better.